JP4968616B2 - Manufacturing method of multilayer printed wiring board - Google Patents

Description

  The present invention has a method of manufacturing a multilayer printed wiring board having two or more layers of circuits, and the circuits are electrically connected (electrically connected) to each other, and a multilayer printed wiring board that can be manufactured by the manufacturing method About.

  The multilayer printed wiring board is known as a technology that enables high-density mounting of components and can connect (means to conduct) the components at the shortest distance. Japanese Patent Application Laid-Open No. 8-288649 describes a method of manufacturing a multilayer printed wiring board by a simple process.

  This method is a method of laminating and pressing a wiring board formed with a circuit on an insulating substrate, an insulating sheet for interlayer adhesion, and a copper foil in this order. Bumps of conductive material (conductive paste) that are deformed by pressurization and heating at the time of the lamination press are provided, through holes are formed in the insulating sheet for interlayer adhesion, the bumps are inserted into the through holes, and copper foil is overlaid. And thermocompression bonding. In this method, during thermocompression bonding, the bump and the insulating sheet flow to form a through hole filled with the conductive paste, and the circuit on the insulating substrate and the copper foil are connected with each other (electrically connected). Is done.

As in this method, a bump made of a deformable conductive material is formed at an interlayer connection portion of a wiring board on which a circuit is formed or a wiring board having a conductive layer capable of forming a circuit, and insulation for interlayer adhesion is formed. A multilayer printed wiring board can be manufactured in a simple process by inserting the bump into a through-hole opened in a sheet, and further superposing a conductive layer such as copper foil or a composite layer including the conductive layer and thermocompression bonding. it can. However, this method has a problem in that the connection between the conductive material and the conductive layer after the thermocompression bonding is poor, and thus the conduction between the circuits is also poor, and the reliability of the multilayer printed wiring board is poor. . This problem is particularly serious when an insulating sheet having a low melt viscosity at the time of thermocompression bonding is used.
JP-A-8-288649

  The present invention provides a multilayer in which bumps made of a conductive material are provided on a wiring board, the bumps are inserted into through holes formed in an insulating sheet for interlayer adhesion, and a conductive layer or a composite layer including a conductive layer is stacked and heat-pressed. A method for manufacturing a printed wiring board, which provides a method in which a connection failure between a conductive material after thermocompression bonding and a conductive layer (including a conductive layer provided on the surface of the composite layer) does not occur. Let it be an issue. The present invention further provides a multilayer printed wiring board that can be manufactured by this manufacturing method, and that has a high connection reliability between a conductive material and a conductive layer, and therefore has a high reliability as a wiring board. It is also an issue to do.

  The inventor believes that the reason for the poor connection between the conductive material after thermocompression bonding and the conductive layer is that the insulating sheet for interlayer adhesion flows and flows before joining the conductive layer facing the conductive material of the bump during thermocompression bonding. It was thought to be due to flowing between the layer and the conductive material. And by providing the conductive material bumps not only on the wiring board side but also on the conductive layer side that is electrically connected to this wiring board, the flowing insulating sheet is prevented from flowing between the conductive layer and the conductive material. The present inventors have found that the occurrence of defects can be prevented and completed the present invention.

That is, the subject of the present invention is a wiring board composed of an insulating layer and a conductive layer, the wiring board A having a bump A of a conductive material deformed by pressure heating on one surface,
An insulating sheet for interlayer adhesion having a through-hole at a position corresponding to the bump A, and a bump B made of a conductive material that is deformed by pressure heating are provided at a position corresponding to the bump A on one surface. Conductive layer B or wiring substrate B having conductive layer B bonded to one surface thereof,
The interlayer adhesive insulating sheet is sandwiched between the wiring board A and the conductive layer B, and the bump A and the bump B are stacked so as to be inserted into the through-hole, and these are stacked and pressed. This is achieved by a method for manufacturing a multilayer printed wiring board characterized by the above (claim 1).

  In the manufacturing method of the present invention described above, the wiring board A and the wiring board B having the conductive layer B or the conductive layer B bonded to one surface thereof are laminated and pressed while sandwiching an insulating sheet for interlayer adhesion. Manufactures printed wiring boards. Here, the wiring board A has one or more conductive layers, has bumps A made of a conductive material that is deformed by pressure heating on one surface, and has an insulating layer. The insulating layer is usually provided between the conductive layer and the bump A, or between the conductive layers when there are two or more conductive layers.

  As the wiring board A, a single-sided wiring board having a conductive layer only on one side of the insulating layer, a conductive layer on both sides of the insulating layer, and these are electrically connected by a through hole plating or a hole filled with a conductive material. Examples thereof include a double-sided wiring board and a multilayer wiring board having a large number of conductive layers separated from each other by an insulating layer, which are conducted by through-hole plating or holes filled with a conductive material. Among them, the wiring substrate A is composed of an insulating substrate which is an insulating layer, and a conductive layer provided on a surface different from the surface of the insulating substrate on which the bump A is provided, and the insulating substrate ( In the case where the insulating layer has a hole filled with a conductive material, and the bump A and the conductive layer are a single-sided wiring board substrate that is electrically connected by the hole, the multilayer printed wiring board of the present invention is manufactured. The method is preferably applied. Claim 2 corresponds to this preferable mode.

  Examples of the insulating layer constituting the wiring board A include resin films mainly composed of polyethylene terephthalate (PET), polyamide such as aramid, polyimide, liquid crystal film, polyester and the like. A resin film mainly composed of polyimide is a heat-resistant film and is preferable because it can meet the demand for higher heat resistance corresponding to the use of lead-free solder. In addition, the insulating substrate can be made thinner and stronger.

  The conductive layer constituting the wiring board A is not particularly limited as long as it is a thin film made of a conductive material, but copper such as copper foil, silver-containing copper foil, beryllium copper alloy foil, brass foil, phosphor bronze foil, etc. An alloy foil or the like is used. As an insulating substrate provided with a conductive layer on one surface, a copper foil-attached resin base material, particularly a polyimide resin base material, on which one side of the copper foil is attached, can be used. The thing with an adhesive agent or the thing bonded together without using an adhesive agent may be used.

  The bump A is a protrusion made of a conductive material that is deformed by pressurization and heating during the lamination press. An example of the conductive material that is deformed by pressure heating is a conductive paste. The conductive paste is obtained by dispersing a conductive filler in a flowable resin. As the conductive filler, fine particles such as silver, copper, Ni, Sn, lead solder, and lead-free solder are preferably used. In addition, fine particles (silver coated copper, silver coated Ni, etc.) obtained by multilayering two or more of these, a mixture, and the like can be used. As the fluid resin, epoxy, polyester, phenol, polyimide, polyamide, and a mixture thereof can be used.

  In the single-sided wiring board base material (hereinafter simply referred to as a single-sided wiring board base material) used in the aspect of claim 2, the bump A is opposite to the surface of the insulating substrate on which the conductive layer is provided. On the surface. When this single-sided wiring board substrate is used, the conductive layer B and the conductive layer B provided with the bumps B each form a different layer circuit, but after the lamination press, there is an interlayer between the conductive layer and the conductive layer B. The insulating substrate is sandwiched together with the adhesive layer formed from the adhesive insulating sheet. Since the insulating sheet for interlayer adhesion is deformed, there is a possibility that a defective part of insulation is generated at the time of laminating press. However, since the insulating substrate is further sandwiched, there is no occurrence of defective insulation and excellent insulation. Is achieved. The height of the bump A is preferably about 10 to 100 μm, and the diameter is preferably about 30 to 300 μm.

  When the wiring board A is the single-sided wiring board base, the conductive layer provided on the surface different from the bump A is electrically connected to the bump A through the hole filled with the conductive material in the insulating substrate. This hole penetrates the insulating substrate and is connected to the bump A and the conductive layer at both ends thereof. As the conductive material filling the holes, the same material as the conductive material used for forming the bump A can be used. For example, the same conductive paste as described above can be used. Even if the wiring board A is other than the single-sided wiring board substrate, the conductive layer provided on the surface other than the surface on which the bump A is provided and the bump A are formed in the insulating layer and filled with the conductive material. Conduction can be made by the formed hole.

The hole filled with the conductive material can be formed by drilling using a laser or the like at a position where interlayer connection of the insulating layer is desired. Preferred examples of the laser include a CO ₂ laser and a UV-YAG laser. After drilling with a laser, the desmear treatment is usually performed by wet desmear treatment, wet blast treatment, plasma treatment, or the like.

  When the conductive material is a conductive paste, the hole is filled with the conductive material, for example, by screen printing. After this screen printing, bumps A made of a conductive paste can be formed by a method in which a conductive paste or the like is further applied thereon by screen printing. It is preferable to form the bumps A by the same material as the conductive material filled in the holes, since both can be easily manufactured by screen printing and the reliability of connection between the two can be increased. Here, the same material means a material composed of the same raw material. Considering the ease of screen printing and the like, the viscosity and the like may be different.

  The conductive layer constituting the wiring board A forms a circuit in the multilayer printed wiring board, but the conductive layer provided on the surface opposite to the surface to be bonded to the insulating sheet for interlayer adhesion, for example, the wiring board As for the conductive layer provided on the surface different from the bump A in the case of the single-sided wiring board substrate, A may be formed before stacking, or may be formed after stacking. The third aspect corresponds to a mode in which the wiring board A is the single-sided wiring board base material, and the conductive layer is formed by a circuit before lamination.

  Circuit formation of the conductive layer can be performed, for example, by etching. For example, after a circuit pattern of a resist layer is formed on a conductive layer, the conductive layer is immersed in an etchant that corrodes to remove portions other than the circuit pattern, and then is performed by chemical etching (wet etching) that removes the resist layer. be able to. Examples of the etchant in this case include a ferric chloride-based etchant mainly composed of ferric chloride, a cupric chloride-based etchant, and an alkali etchant.

  The insulating sheet for interlayer adhesion is obtained by forming a through hole at a position corresponding to the hole in a sheet made of an adhesive that is deformed by heating and pressing. Forming the through hole at a position corresponding to the hole means forming the through hole so that the bump A is inserted into the through hole when the wiring board A and the interlayer adhesive insulating sheet are overlapped. To do. The method for forming the through hole is not particularly limited, and it is possible to employ a method of drilling with a laser, a method of mechanically drilling using a drill, a mold, or the like.

As the adhesive for forming the insulating sheet for interlayer adhesion, an adhesive made of a thermoplastic resin such as epoxy, acrylic, polyimide, thermoplastic polyimide, or a mixture thereof is preferably used. As an insulating sheet for interlayer adhesion, a sheet having a thickness of about 10 μm to 100 μm is usually used, preferably 15 μm to 70 μm. If the thickness is less than 10 μm, the adhesive does not spread sufficiently during the laminating press for interlayer adhesion, and the gaps between the bumps A and B and the adhesive are difficult to be eliminated. On the other hand, when the thickness exceeds 100 μm, it becomes difficult to form bumps A and / or bumps B having a projection length corresponding to this thickness. In addition, the range of the minimum value of the melt viscosity of the adhesive forming the insulating sheet for interlayer adhesion is not particularly limited. However, an adhesive having this value at 100 to 200 ° C. of 1 × 10 ³ Pa · s or less is liable to flow at the time of laminating press. According to the present invention, insulation failure is unlikely to occur even when this adhesive is used. Therefore, the effect of the present invention becomes remarkable when this adhesive is used.

  The conductive layer B is a thin film made of a conductive material, and is not particularly limited. Usually, a copper alloy foil such as a copper foil, a silver-containing copper foil, a beryllium copper alloy foil, a brass foil, or a phosphor bronze foil is used. . The present invention is characterized in that a bump B of a conductive material that is deformed by pressure heating is provided at a position corresponding to the bump A of the conductive layer B, that is, a position where interlayer bonding is performed.

  Similarly to the bump A, the bump B is also a protrusion made of a conductive material that is deformed by pressure heating at the time of the lamination press. As the conductive material that is deformed by pressure heating, the same conductive paste as in the case of the bump A is exemplified. When the conductive paste is used, the bumps B can also be formed by screen printing.

  The height of the bump B is preferably about 5 to 100 μm, and the diameter is preferably about 20 to 300 μm. As will be described later, the diameter of the bump B may be equal to or larger than the diameter of the through hole formed in the interlayer adhesive insulating sheet, but is preferably smaller.

  In the method for producing a multilayer printed wiring board of the present invention, an insulating sheet for interlayer adhesion is sandwiched between a wiring board A and a wiring board B in which a conductive layer B or a conductive layer B is bonded to one surface thereof, and a bump A Then, the wiring board A, the interlayer adhesion insulating sheet, and the conductive layer B or the wiring board B having the conductive layer B are stacked, and these are laminated and pressed so that the bumps B are inserted into the through holes. That is, as the material to be bonded to the insulating sheet for interlayer adhesion, a film composed only of the conductive layer B, for example, a film composed only of a thin film of a conductive material such as copper foil may be used. The bonded wiring board B may be used. According to a fourth aspect of the present invention, there is provided a method for manufacturing the multilayer printed wiring board, wherein the wiring substrate B having the conductive layer B bonded to one surface thereof is used.

  The wiring board B in which the conductive layer B is bonded to one surface is provided with the conductive layer B having the bumps B formed on one surface of the substrate including the insulating layer. As such a wiring board B, a single-sided wiring board having a conductive layer B only on one side of an insulating layer, for example, a conductive layer B bonded to an insulating substrate, and other insulating substrates together with the conductive layer B A double-sided wiring board that has a conductive layer on the surface and is electrically connected by through-hole plating or a hole filled with a conductive material, or has a conductive layer B on one side and is further separated by an insulating layer. In addition, a multilayer wiring board having a large number of conductive layers, which are connected to each other by through-hole plating, holes filled with a conductive material, or the like can be used.

  Examples of the insulating layer constituting the wiring board B include resin films mainly composed of polyethylene terephthalate (PET), polyamide such as aramid, polyimide, liquid crystal film, polyester, and the like, similar to the insulating layer of the wiring board A. Further, as the conductive layers other than the conductive layer B constituting the wiring board B, a thin film made of a conductive material, such as a copper foil, is used similarly to the conductive layer constituting the wiring board A. As the wiring board B which is a single-sided wiring board, a copper foil-attached resin base material with a copper foil, particularly a polyimide resin base material can be used, and an adhesive is provided between the copper foil and the resin base material. However, it may be bonded without using an adhesive.

  The conductive layer B forms a circuit of a multilayer printed wiring board. When only the conductive layer B is bonded, this circuit formation is performed after lamination. On the other hand, when the wiring board B in which the conductive layer B is bonded to one surface is used, it is performed before the lamination. The circuit formation of the conductive layer B can be performed by performing etching as in the case of the conductive layer of the wiring board A. The etching method is the same as described above.

  The lamination press can be performed by heating and pressurizing with a cure press or a vacuum press. In order to suppress the generation of voids between the laminates, a vacuum press is preferably employed.

  When the diameter of the through-hole formed in the insulating sheet for interlayer adhesion is larger than the diameter of the bump A and the bump B, the gap between the adhesive forming the insulating sheet for interlayer adhesion and the bump is before the start of the lamination press. However, this gap is eliminated by spreading until the adhesive contacts the bumps by the lamination press. Further, the bump A and the bump B are also deformed by the laminating press, and the gap is eliminated. Further, the bump A and the bump B are integrated and filled in the through hole by the lamination press.

  In the prior art in which the bump B is not provided, the adhesive forming the interlayer adhesive insulating sheet spreads between the bump A and the conductive layer B at the time of the laminating press, resulting in poor electrical connection between the bump A and the conductive layer B. Although it is likely to occur, in the present invention in which the bump B is provided, this problem does not occur and a good connection is achieved. In this way, the wiring board A and the wiring board B having the conductive layer B bonded to one surface thereof are firmly bonded by the interlayer adhesive insulating sheet, and excellent connection reliability is obtained.

  When the wiring board B in which the conductive layer B is bonded to the insulating substrate is used, a hole is formed in the insulating substrate, the hole is filled with a conductive material, and the same as the bump A is further formed thereon. Bumps of conductive material can be formed.

  Then, in the same manner as described above, by laminating and pressing an interlayer adhesive insulating sheet having a through-hole and a wiring substrate B bonded with the conductive layer B on one surface thereof, it is composed of a multi-layer circuit, and these are mutually connected. A conductive multilayer printed wiring board can be manufactured. By repeating the same operation, a multilayer printed wiring board composed of multiple layers can be manufactured.

  The diameter of the through hole of the interlayer adhesive insulating sheet is preferably 0.5 to 5 times the diameter of the bump A and the bump B. If it is less than 0.5 times, the alignment when the insulating sheet for interlayer adhesion and the wiring board substrate are overlapped is not easy, and the case where the bumps are not inserted into the through holes tends to occur. On the other hand, when it is 5 times or more, it becomes difficult to spread until the adhesive comes into contact with the bumps at the time of the lamination press, and there is a possibility that the gap between the two is not eliminated. More preferably, it is 1.2 to 3 times, and alignment becomes easier, and generation of a gap can be prevented more reliably. Claim 5 corresponds to this preferable mode.

  The present invention further includes a multilayer printed wiring board having a circuit having two or more layers, an insulating layer sandwiched between the circuits, and a conductive portion passing through the insulating layer and conducting between the circuits sandwiching the insulating layer. The multilayer printed wiring board is characterized in that an area of a cross section obtained by cutting the conductive portion by a plane parallel to the circuit is small at the central portion of the thickness of the insulating layer and large at the contact portion with the circuit (claim). Item 6). By the manufacturing method of the present invention, a multilayer printed wiring board having the features of claim 6 can be easily manufactured. That is, the insulating layer of the multilayer printed wiring board is formed by the insulating layer on which the interlayer adhesion insulating sheet and the bump A of the wiring board A are formed in the manufacturing method of the present invention, and the conductive portion is formed by the bump A and the bump B. A circuit of two or more layers is formed by the conductive layer and conductive layer B of the wiring board A, and possibly other conductive layers of the wiring board B.

  The multilayer printed wiring board of the present invention is characterized in that the cross-sectional area of the conductive portion is large at the contact portion with the circuit. Therefore, the contact area between the circuit and the conductive portion is large, and poor electrical connection is unlikely to occur, and high reliability can be obtained as a multilayer printed wiring board.

  According to the method for producing a multilayer printed wiring board of the present invention, a conductive material bump is provided on a wiring board, the bump is inserted into a through hole opened in an insulating sheet for interlayer adhesion, and another conductive layer or conductive layer. It is a multilayer printed wiring board in which multilayer circuits are laminated by a simple process of superimposing other wiring boards on the surface and thermocompression bonding, and the connection failure between the conductive material and the conductive layer after thermocompression bonding Thus, a multilayer printed wiring board having high reliability can be manufactured. The multilayer printed wiring board of the present invention is a multilayer printed wiring board having high reliability of connection between a conductive material and a conductive layer and high reliability as a wiring board.

  Next, the best mode for carrying out the present invention will be described by way of examples. In addition, this invention is not limited to the form of this Example, The change to another form is also possible unless the meaning of this invention is impaired.

Example 1
FIG. 1 is a schematic cross-sectional view showing a state in which a single-sided wiring board substrate, an interlayer adhesive insulating sheet, and a conductive layer B produced as described below are stacked in order to perform lamination pressing.

[Production of single-sided wiring board substrate]
A bottomed hole 3 (opened) is applied to a single-sided copper-clad substrate (PI: 25 μm, copper thickness: 18 μm) bonded to one side of the polyimide film 1 (PI) without using an adhesive by a YAG laser. The aperture was 100 μm) and wet desmearing was performed with alkali and potassium permanganate. A total of eight holes 3 were formed.

  In each hole 3, an epoxy resin composed of 70 parts by weight of a bisphenol A type epoxy resin (epoxy equivalents 7000-8500) and 30 parts by weight of a bisphenol F type epoxy resin (epoxy equivalents 160-170) is dissolved in butyl carbitol acetate. Make a solution. To this, an imidazole-based latent curing agent is added, and the silver particles are dispersed with a total solid content of 55% by volume to obtain a silver paste 4. The silver paste 4 is filled into each hole 3 by screen printing, and is temporarily cured. Further, the silver paste 41 having a solid content made of the same component as the silver paste 4 and having a high viscosity is screen-printed, A total of eight bumps A (convex portions) having a (maximum) diameter of 200 μm and a height of 60 μm were formed, and temporary curing was performed.

[Preparation of insulating sheet for interlayer adhesion]
Adhesive sheet 5 (made by Shin-Kobe Electric Co., Ltd., trade name: EA541, melt viscosity at 120 ° C .: 60 Pa · s ) obtained by impregnating an epoxy resin into an aramid nonwoven fabric having a thickness of 35 μm (on bump A) A through hole 6 having a diameter of 300 μm was formed at a corresponding position) using a drill.

[Preparation of conductive layer B]
The same silver paste 8 as the silver paste 41 used for the production of the single-sided wiring board base material is printed at a position where the interlayer connection of the copper foil 7 having a thickness of 18 μm (a position corresponding to the bump A) is performed, and temporary curing is performed. A bump B having a (maximum) diameter of 200 μm and a height of 60 μm was formed to obtain a conductive layer B.

[Lamination press]
After superposing the single-sided wiring board substrate, the interlayer adhesive insulating sheet and the conductive layer B so as to insert the bumps A and B into the through holes of the interlayer adhesive insulation, as shown in FIG. A joining process was performed by vacuum pressing, and then a circuit was formed so that the eight interlayer connection portions were daisy chained to produce a multilayer printed wiring board.

Example 2
Instead of the copper foil 7, a single-sided copper-clad substrate (PI: 25 μm, copper thickness: 18 μm) in which the copper foil 10 is bonded to one side of the polyimide film 9 (PI) without using an adhesive is etched in advance. Multilayer printed wiring as in Example 1, except that a substrate on which a circuit was fabricated and a bump substrate B having a (maximum) diameter of 200 μm and a height of 60 μm was formed on this circuit to obtain a wiring substrate B A plate was made. FIG. 2 is a schematic cross-sectional view showing a state in which the single-sided wiring board base material, the interlayer adhesion insulating sheet, and the wiring board B in this example are superposed for the lamination press.

  FIG. 3 is a schematic cross-sectional view showing the multilayer printed wiring board thus obtained. As is clear from FIG. 3, the conductive portion 11 (connection portion between the conductive layers) of this multilayer printed wiring board has a cross-sectional area obtained by cutting the conductive portion by a plane parallel to the circuit, and the center of the thickness of the insulating layer. When the diameter was measured, the central part was 210 μm and the contact part was 250 μm.

Conventional Example A multilayer printed wiring board was produced in the same manner as in Example 1 except that the silver paste was not printed on the portion of the copper foil 7 where the interlayer connection was made. FIG. 4 is a schematic cross-sectional view showing a state in which the single-sided wiring board substrate, the interlayer adhesion insulating sheet, and the conductive layer in this example are overlapped for the lamination press.

[Evaluation]
The multilayer printed wiring boards obtained in Examples 1 and 2 and the conventional example were inspected to determine whether or not predetermined continuity was obtained. The inspection was performed by measuring the resistance from both ends of the daisy chain by the 4-terminal method. The results (number of inspections where predetermined continuity was not obtained / total number of inspections: ratio of inspection where predetermined continuity was obtained) are shown below.
Example 1 0/12: 100%
Example 2 0/12: 100%
Conventional example 12/12: 0%

  As is clear from this result, a multilayer printed wiring board having high reliability can be obtained by the method of the present invention (Examples 1 and 2).

3 is a schematic cross-sectional view showing an outline of one step in Example 1. FIG. 10 is a schematic cross-sectional view showing an outline of one step in Example 2. FIG. 6 is a schematic cross-sectional view showing a multilayer printed wiring board obtained in Example 2. FIG. It is a schematic sectional drawing which shows the outline of 1 process of a prior art example.

Explanation of symbols

1, 9 Polyimide film 2, 7, 10 Copper foil 3, Hole 4, 8, 41 Silver paste 5, Adhesive sheet 6, Through hole

Claims (3)

An insulating substrate that is an insulating layer, a bump A of a conductive material that is deformed by pressure heating provided on one surface of the insulating substrate, and a surface of the insulating substrate on which the bump A is provided; Consists of conductive layers provided on different surfaces,
A wiring board which is a single-sided wiring board substrate in which a hole filled with a conductive material is provided in contact with the bottom surface of the bump A in the insulating substrate, and the bump A and the conductive layer are electrically connected by the hole. A,
An insulating sheet for interlayer adhesion having a through-hole at a position corresponding to the bump A, and a bump B made of a conductive material that is deformed by pressure heating are provided at a position corresponding to the bump A on one surface. Conductive layer B or wiring substrate B having conductive layer B bonded to one surface thereof,
The interlayer adhesive insulating sheet is sandwiched between the wiring board A and the conductive layer B, and the bump A and the bump B are stacked so as to be inserted into the through-hole, and these are stacked and pressed. A method for producing a multilayer printed wiring board characterized by the above.   The method for manufacturing a multilayer printed wiring board according to claim 1, wherein the conductive layer is formed with a circuit. Diameter of the layer indirectly wearing insulating sheet through hole of, the diameter of the bump A, and the bumps B, the multilayer printed wiring board according to claim 1 or claim 2, characterized in that a 1.2 to 3-fold Production method.

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